A study was conducted to investigate the relationship between asthma prevalence
ID: 3183697 • Letter: A
Question
A study was conducted to investigate the relationship between asthma prevalence and annual rainfall in countries around the world. A random sample of 11 countries was obtained. The total annual rainfall (x, in mm) was recorded for each country, as well as the percentage of adults, 22-44 years old, treated for ashtma(y). The following summary statistics were reported.
Sxx = 178,661
Syy = 49.2655
Sxy = 380.955
xbar = 792.636
ybar = 5.26
a.) find the estimated regression line.
b.)Complete the ANOVA summary table, and conduct an F test for a significant regression. Does annual rainfall help to explain the variation in ashtma prevalence? Justify your answer.
c.) Find a 95% prediction interval for an observed asthma prevalence if the total annual rainfall is 1000mm. Comment on anything odd about this interval.
Explanation / Answer
y = a + bx
b = (nSxy - Sx.Sy)/(nSxx - (Sx)^2)
b = (11*380.955 - (792.636*11)*(5.26*11)/(11*178661 - (792.636*11)^2)
= 0.006756
a = ybar - b*xbar
= 5.26 - 0.006756*792.636
=-0.09505
y = -0.09505 + 0.006756 x
b)
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.